diff --git a/LibC/signal.cpp b/LibC/signal.cpp
index c198650c99..3bbcc2a2ae 100644
--- a/LibC/signal.cpp
+++ b/LibC/signal.cpp
@@ -28,5 +28,47 @@ int sigaction(int signum, const struct sigaction* act, struct sigaction* old_act
     __RETURN_WITH_ERRNO(rc, rc, -1);
 }
 
+int sigemptyset(sigset_t* set)
+{
+    *set = 0;
+    return 0;
 }
 
+int sigfillset(sigset_t* set)
+{
+    *set = 0xffffffff;
+    return 0;
+}
+
+int sigaddset(sigset_t* set, int sig)
+{
+    if (sig < 1 || sig > 32) {
+        errno = EINVAL;
+        return -1;
+    }
+    *set |= 1 << (sig - 1);
+    return 0;
+}
+
+int sigdelset(sigset_t* set, int sig)
+{
+    if (sig < 1 || sig > 32) {
+        errno = EINVAL;
+        return -1;
+    }
+    *set &= ~(1 << (sig - 1));
+    return 0;
+}
+
+int sigismember(const sigset_t* set, int sig)
+{
+    if (sig < 1 || sig > 32) {
+        errno = EINVAL;
+        return -1;
+    }
+    if (*set & (1 << (sig - 1)))
+        return 1;
+    return 0;
+}
+
+}
diff --git a/LibC/signal.h b/LibC/signal.h
index 452840e874..03e2f03d4a 100644
--- a/LibC/signal.h
+++ b/LibC/signal.h
@@ -22,7 +22,12 @@ struct sigaction {
 
 int kill(pid_t, int sig);
 sighandler_t signal(int sig, sighandler_t);
-int sigaction(int signum, const struct sigaction* act, struct sigaction* old_act);
+int sigaction(int sig, const struct sigaction* act, struct sigaction* old_act);
+int sigemptyset(sigset_t*);
+int sigfillset(sigset_t*);
+int sigaddset(sigset_t*, int sig);
+int sigdelset(sigset_t*, int sig);
+int sigismember(const sigset_t*, int sig);
 
 #define SIG_DFL ((__sighandler_t)0)
 #define SIG_ERR ((__sighandler_t)-1)